A team at the USF Health Byrd Alzheimer’s Institute led by Peter Mouton, PhD, a professor in the USF Health Morsani College of Medicine’s Department of Pathology and Cell Biology, worked with principal investigator Eric Courchesne, PhD, and colleagues at the University of California San Diego (UCSD) on the study.

Previously published research led by USCD neuroscientist Courchesne was also done in collaboration with Dr. Mouton’s group; that study reported an overabundance of neurons in the prefrontal cortex of children with autism — 60 to 70 percent more than in age-matched controls.

The current study analyzed postmortem brain tissue from children with and without autism, all between ages 2 and 15.

Blinded stereology analyses by USF Health quantified the densities of neurons (brain cells) inside and outside patches in the cerebral cortex of the brains from autistic children, and compared these to the same regions in brains from non-affected children. The researchers found a highly disorganized pattern of neurons in the cerebral cortex of children with autism.

“Since the number and pattern of neurons is set by the time of birth in humans, these findings confirm that autism starts before birth,” Dr. Mouton said. “Secondly, our study points directly to genetic mutations that regulate the normal pattern of cortical brain cells as the likely cause of autism.”

The study was supported in part by the National Institute of Mental Health.

Over the last five years, Courchesne and colleagues have worked with Mouton, a NIMH grantee, who has developed computerized stereology systems to accurately and efficiently count brain cells in an unbiased manner. For neuropathology studies, Mouton uses a computerized stereology system developed and patented by his company, the Stereologer Resource Center.